In the liquid crystal display panel manufacturing industry, since a low temperature poly-silicon technology (LTPS) has better electron mobility, it has gradually become the innovation direction of the LCD panel technology.
During the low temperature poly-silicon manufacturing process, before a laser annealing treatment, a glass substrate is provided with an amorphous silicon, which requires cleaning by a cleaning agent (for example, hydrofluoric acid, HF) for cleaning the silicon film on the surface of the glass substrate, in which the hydrofluoric acid is configured to wash off glitches on the glass substrate. After the glass substrate is cleaned by the hydrofluoric acid cleaning agent, clean dry air (CDA) is used to blow off the liquid agent on the glass substrate, and then an oxide film is formed on the surface of the glass substrate which has been cleaned by hydrofluoric acid. Finally, the laser annealing treatment is processed to form a poly-silicon on the glass substrate, then a low temperature poly-silicon thin film is formed.
However, in practice, the inventors have found that in the conventional low temperature poly-silicon manufacturing process, the oxide film is not uniform, or large protrusions are formed during the laser annealing process, thereby resulting in high surface roughness of the low temperature poly-silicon thin film and a poor crystalline effect.